CN116536714A

CN116536714A - Manufacturing method for electroplating thick gold on inner wall of electroformed pipe

Info

Publication number: CN116536714A
Application number: CN202310575284.6A
Authority: CN
Inventors: 刘晓峰
Original assignee: Dongguan Huaming Nameplate Co ltd
Current assignee: Dongguan Huaming Nameplate Co ltd
Priority date: 2023-05-22
Filing date: 2023-05-22
Publication date: 2023-08-04

Abstract

The invention discloses a manufacturing method of thick gold plated on the inner wall of an electroformed pipe, which comprises a mandrel, wherein the outer surface of the mandrel is subjected to cleaning treatment and degreasing treatment; then soaking the treated core mould to form a passivation separating layer on the outer surface of the core mould; then gold plating is carried out on the mandrel with the passivation separation layer, so as to obtain the mandrel with the gold plating layer; then, carrying out external surface pretreatment on the mandrel with the gold-plating layer to form a metal transition layer on the external surface of the gold-plating layer; then, carrying out electroforming treatment on the mandrel with the metal transition layer to form an electroformed layer, thereby obtaining a formed electroformed product; finally, separating the formed electroformed product from the core mold by a physical demolding mode; according to the invention, the gold plating layer is firstly manufactured, and then the outer electroplated layer is added, so that the thickness of the inner gold plating piece can be controlled, the gold plating layer with the required thickness can be formed according to actual requirements, and then the outer electroplated layer is formed, so that the formed product meets the precision requirement.

Description

Manufacturing method for electroplating thick gold on inner wall of electroformed pipe

Technical Field

The invention relates to the technical field of electroforming, in particular to a manufacturing method of thick gold plated on the inner wall of an electroformed pipe.

Background

With the continuous development and progress of technology, modern precision parts are more and more, and equipment for manufacturing precision parts is particularly important, and the machining precision of the equipment can often determine the forming precision of products, and most of precision parts are used in precision and important equipment, such as aerospace equipment, meters, instruments, optical equipment and micro robots, which are small in size and extremely high in precision requirement, so that great machining difficulty is brought to manufacturers.

At present, the miniature pipe body in the market cannot be processed by adopting a traditional processing mode, electroplating processing is needed, and the electroplating processing can be used for forming fine parts which cannot be processed in the traditional manufacturing industry, but the processing cost is high, the thickness of a coating of a formed product cannot be ensured, and more defective products and increased cost are caused.

In the process of processing the electroforming tube, the outermost electroforming layer is required to be processed first and then gold plating is carried out, so that the thickness of the inner gold plating layer cannot meet the requirement, the product is scrapped, the resource is wasted, and the high production and manufacturing cost is increased for enterprises.

Therefore, a new technical solution is needed to solve the above problems.

Disclosure of Invention

In view of the above, the present invention is directed to the drawbacks of the prior art, and its main purpose is to provide a method for manufacturing thick gold plated on the inner wall of electroformed tubes.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

a method for manufacturing thick gold plated on the inner wall of electroformed pipe comprises a mandrel,

s1: the outer surface of the core mold is subjected to cleaning treatment and degreasing treatment, and residues attached to the outer surface of the core mold are eliminated;

s2: then soaking the treated core mould to form a passivation separating layer on the outer surface of the core mould;

s3: then, carrying out gold plating on the mandrel with the passivation separation layer in an electrodeposition mode to obtain a mandrel with a gold plating layer;

s4: then, carrying out external surface pretreatment on the mandrel with the gold-plating layer to form a metal transition layer on the external surface of the gold-plating layer;

s5: then, electroforming the same metal material on the mandrel with the metal transition layer to form an electroformed layer, thereby obtaining a formed electroformed product;

s6: finally, the formed electroformed product is separated from the core mold by means of physical demolding.

Preferably, the core mold is made of stainless steel wire or red copper wire material.

Preferably, the degreasing treatment is ultrasonic chemical degreasing, and the mandrel is put into an electrolytic tank with an electrolytic solution for electrolytic treatment, wherein the electrolytic solution comprises: 20g-40g/L of sodium hydroxide, 20g-30g/L of sodium carbonate, 5g-10g/L of trisodium phosphate, 5g-15g/L of sodium silicate, 1g-3g/L of OP emulsifier, 70-90 ℃ of core mold treatment process temperature, and 3-5 minutes of degreasing time of the core mold in an electrolytic solution.

Preferably, the passivation separation layer is a passivation film attached to the outer surface of the mandrel, the passivation film is prepared by soaking 15g/L of potassium dichromate solution, the soaking time of the mandrel is 1-2 minutes, and the passivation film is used for ensuring that the gold-plating layer and the mandrel have no binding force and are easy to be demolded.

As one preferable, the method for preparing the gold plating layer includes: potassium gold: 0.8g-3.0g/L, potassium citrate: 20g-40g/L, conductive salt and brightening agent, the preparation temperature of the gold plating layer is 50-60 ℃, and the PH value of the gold plating process parameter is 4.0-4.5.

Preferably, the gold plating layer has a thickness of 1.5 to 10 μm.

Preferably, the transition layer is made of nickel metal material or copper metal material, and the transition layer enables the electroformed layer to be better combined with the gold-plating layer.

As one preferable example, the transition layer is a nickel pre-plating layer made of nickel metal material, and the preparation method comprises: the core mould with the gold plating layer is put into the solution, kept stand in the solution for 10-20 seconds, and matched with current of 3-5A/square decimeter, nickel preplating can be attached to the outer surface of the gold plating layer.

Preferably, the electroformed layer is electroplated nickel, and the method for preparing electroplated nickel comprises the following steps: the method comprises the steps of putting a solution prepared from 500g/L of nickel sulfamate, 45g/L of boric acid and 10g/L of nickel chloride into the solution with the temperature of 50-60 ℃, and carrying out electroplating processing by matching with current with the current of 3-5A/square decimeter, so that the thickness of an electroplated layer is made to be 8-100 microns, and the PH value of electroplating process parameters is 4-4.5.

Preferably, the physical demolding mode is quick-frozen demolding, heating demolding or stretching core mold to change the diameter, so as to perform drawing demolding.

Compared with the prior art, the invention has obvious advantages and beneficial effects, and in particular, the technical scheme can be as follows:

according to the invention, the gold plating layer is firstly manufactured, and then the outer electroplated layer is added, so that the thickness of the inner gold plating piece can be controlled, the gold plating layer with the required thickness can be formed according to actual requirements, and then the outer electroplated layer is formed, so that the formed product meets the precision requirement.

The processing sequence of the invention is as follows: firstly degreasing the core mould, and then forming a layer of passivation separation on the outer surface of the core mould so as to facilitate the follow-up demoulding of the core mould, avoid damage to the gold plating layer in the process of separating the core mould, and effectively play a role in protection; the outer surface of the gold plating layer is pre-plated with a transition layer, so that the binding force between the electroplated layer and the gold plating layer is increased, the connection strength between the electroplated layer and the gold plating layer is enhanced, and finally, the electroplated layer is processed on the outer surface of the transition layer, and the metal material of the electroplated layer is the same as the material of the transition layer, so that the electroplated layer can be better adhered with the transition layer, and the stability of the electroplated layer is ensured.

The invention can prepare the electroformed tube with the gold plating layer of 10 micrometers in thickness, has more precise size requirement, adopts the stainless steel wire or the red copper wire as the core die, is convenient for demoulding in a physical mode in the later period, such as heating, quick freezing or pulling the core die to reduce the diameter of the core die, realizes physical quick demoulding, reduces the corrosion of chemical solution to the inside, and ensures the connection strength and the precision requirement of each layer of the product.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required for the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic overall sectional structure of the present invention.

Wherein, each reference sign in the figure:

10. a core mold; 20. passivating the separation layer; 30. a gold plating layer; 40. a transition layer; 50. plating layers.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved by the present application more clear, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.

It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

It is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate description of the present application and simplify description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be configured and operated in a particular orientation, and therefore should not be construed as limiting the present application.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent.

Referring to fig. 1: a process for plating thick gold on the inner surface of electroformed pipe includes such steps as preparing core mould from stainless steel wire or red copper wire,

Specifically, ultrasonic chemical degreasing is adopted in degreasing treatment, and a stainless steel wire or a core die of a purple copper wire is placed into an electrolytic tank with an electrolytic solution to carry out electrolytic treatment, so that redundant residues are removed from the outer surface of the core die, and the residues are prevented from being mixed into an electroplated layer in the electroplating process to influence the forming of a product. The electrolytic solution comprises: 20g-40g/L of sodium hydroxide, 20g-30g/L of sodium carbonate, 5g-10g/L of trisodium phosphate, 5g-15g/L of sodium silicate and 1g-3g/L of OP emulsifier, wherein the process temperature for treating the core mold is 70-90 ℃, the degreasing time of the core mold in an electrolytic solution is 3-5 minutes, and the attached residues can be removed better, so that the outer surface of the core mold is smooth and has no residues, and the subsequent electroplating processing is facilitated.

Further, the passivation separation layer is a passivation film attached to the outer surface of the core mold, the preparation method of the passivation film is that the core mold is soaked in 15g/L potassium dichromate solution for 1-2 minutes, so that a thin passivation film is formed on the outer surface of the core mold, the passivation film can prevent a gold-plating layer from being directly adhered to the core mold, the gold-plating layer and the core mold have no binding force, demolding is easier, damage and injury to the gold-plating layer caused by demolding of the core mold are effectively avoided, and the integrity of the gold-plating layer is protected.

Further, the preparation method of the gold plating layer comprises the following steps: potassium gold: 0.8g-3.0g/L, potassium citrate: the gold plating solution is prepared from 20g-40g/L, conductive salt and brightening agent, the preparation temperature of the gold plating layer is 50-60 ℃, the PH value of the gold plating process parameter is 4.0-4.5, the core mould with the passivation separation layer is put into the gold plating solution to carry out gold plating, so that the gold plating layer is formed on the core mould, the thickness of the gold plating layer is 1.5-10 microns, and finer and more precise electroplating products can be formed through the technology, so that the use requirements of finer and more precise can be met.

In this embodiment, the transition layer is made of a nickel metal material or a copper metal material, a nickel plating or copper plating transition layer is attached to the outer surface of the gold plating layer in advance by performing a preplating treatment on the outer surface of the gold plating layer, and the subsequent electroforming layer can be better combined with the gold plating layer by preplating the transition layer, because the same material is used as the electroplated layer, the connection strength between the nickel plating layer and the copper plating layer can be better combined, and the stripping condition is avoided.

Further, the transition layer is a nickel pre-plating layer made of nickel metal material, and the preparation method comprises the following steps: the core mould with the gold-plating layer is placed into the solution by adopting the solution prepared by mixing 240g/L of nickel chloride and 100ml/L of hydrochloric acid, kept stand in the solution for 10-20 seconds, and matched with the current of 3-5A/square decimeter, the nickel preplating can be better attached to the outer surface of the gold-plating layer, and the transition layer can be uniformly attached to and combined with the gold-plating layer.

Further, the electroformed layer is electroplated nickel, and the preparation method of the electroplated nickel comprises the following steps: the method comprises the steps of putting a core mould with a transition layer into a solution with the temperature of 50-60 ℃ and carrying out electroplating processing by matching with current with the current of 3-5A/square decimeter, wherein the thickness of an electroplated layer formed by processing is 8-100 micrometers, the PH value of electroplating technological parameters is 4-4.5, and the electroplating is carried out by adopting the same metal material as the transition layer, so that the connection firmness between the electroplated layer and the transition layer can be improved, and the electroplated layer and the gold-plated layer can be stably connected.

In actual use, to the electroplating product that has been shaped, still need break away from inside mandrel, through adopting the mode of physical drawing of patterns, can effectually guarantee that inside cladding material does not receive the destruction of chemical solvent, avoid destroying inside gilding layer that has been shaped, further protect electroplating product's integrality, specifically, the mode of physical drawing of patterns is quick-freeze drawing of patterns, heating drawing of patterns or the mode of tensile mandrel, and wherein the drawing of patterns is used for changing the diameter of mandrel, makes its diameter be less than the cavity internal diameter of electroforming product to can take out it through drawing formula drawing of patterns.

The foregoing description of the preferred embodiments of the present invention has been provided for the purpose of illustrating the general principles of the present invention and is not to be construed as limiting the scope of the invention in any way. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention, and other embodiments of the present invention as will occur to those skilled in the art without the exercise of inventive faculty, are intended to be included within the scope of the present invention.

Claims

1. The manufacturing method of the thick gold plated on the inner wall of the electroformed pipe comprises a mandrel, and is characterized in that:

2. The method for manufacturing the thick gold plated on the inner wall of the electroformed pipe according to claim 1, wherein: the core mould is made of stainless steel wires or red copper wire materials.

3. The method for manufacturing the thick gold plated on the inner wall of the electroformed pipe according to claim 1, wherein: the degreasing treatment adopts ultrasonic chemical degreasing, the mandrel is put into an electrolytic tank with electrolytic solution for electrolytic treatment, and the electrolytic solution comprises: 20g-40g/L of sodium hydroxide, 20g-30g/L of sodium carbonate, 5g-10g/L of trisodium phosphate, 5g-15g/L of sodium silicate, 1g-3g/L of OP emulsifier, 70-90 ℃ of core mold treatment process temperature, and 3-5 minutes of degreasing time of the core mold in an electrolytic solution.

4. The method for manufacturing the thick gold plated on the inner wall of the electroformed pipe according to claim 1, wherein: the passivation separation layer is a passivation film attached to the outer surface of the core mold, the passivation film is prepared by soaking 15g/L of potassium dichromate solution, the soaking time of the core mold is 1-2 minutes, and the passivation film is used for enabling the gold plating layer and the core mold not to have binding force and easy demolding.

5. The method for manufacturing the thick gold plated on the inner wall of the electroformed pipe according to claim 1, wherein: the preparation method of the gold-plating layer comprises the following steps: potassium gold: 0.8g-3.0g/L, potassium citrate: 20g-40g/L, conductive salt and brightening agent, the preparation temperature of the gold plating layer is 50-60 ℃, and the PH value of the gold plating process parameter is 4.0-4.5.

6. The method for manufacturing the electroformed pipe inner wall plated with thick gold according to claim 1 or 5, wherein: the thickness of the gold-plating layer is 1.5 micrometers to 10 micrometers.

7. The method for manufacturing the thick gold plated on the inner wall of the electroformed pipe according to claim 1, wherein: the transition layer is made of nickel metal material or copper metal material, and the transition layer enables the electroformed layer to be better combined with the gold-plating layer.

8. The method for manufacturing the thick gold plated on the inner wall of the electroformed pipe according to claim 7, wherein: the transition layer adopts a nickel pre-plating layer made of nickel metal material, and the preparation method comprises the following steps: the core mould with the gold plating layer is put into the solution, kept stand in the solution for 10-20 seconds, and matched with current of 3-5A/square decimeter, nickel preplating can be attached to the outer surface of the gold plating layer.

9. The method for manufacturing the thick gold plated on the inner wall of the electroformed pipe according to claim 1, wherein: the electroformed layer is electroplated nickel, and the preparation method of the electroplated nickel comprises the following steps: the method comprises the steps of putting a solution prepared from 500g/L of nickel sulfamate, 45g/L of boric acid and 10g/L of nickel chloride into the solution with the temperature of 50-60 ℃, and carrying out electroplating processing by matching with current with the current of 3-5A/square decimeter, so that the thickness of an electroplated layer is made to be 8-100 microns, and the PH value of electroplating process parameters is 4-4.5.

10. The method for manufacturing the thick gold plated on the inner wall of the electroformed pipe according to claim 1, wherein: the physical demoulding mode is quick-frozen demoulding, heating demoulding or stretching mandrel diameter change, so as to carry out drawing type demoulding.